CHEMOTHERAPY-INDUCED MOBILIZATION OF KARYOTYPICALLY NORMAL PBSC FOR AUTOGRAFTING IN CML

High-dose chemotherapy with autologous transplantation of in vivo purg ed PBSC is a new and interesting therapeutic option for CML patients n ot eligible for allogeneic transplantation. We investigated the feasib ility and toxicity of this approach in 57 patients with Ph-positive CM L. For mobilization of Ph-negative PBSC, patients were treated either with '5 + 2/7 + 3'-type chemotherapy or with 'mini-ICE/ICE' chemothera py followed by administration of G-CSF, Fourteen patients were in earl y chronic phase, 30 patients in late chronic phase and 13 patients in accelerated phase (AP) or blast crisis (BC), Cytogenetic responses in the PBSC harvests were dependent on both disease stage and type of che motherapy: in late chronic phase and AP/BC, a complete or major cytoge netic response could be obtained in nine out of 13 patients treated wi th 'mini-ICE/ICE' but only in three out of 23 patients treated with '5 + 2/7 + 3' chemotherapy, However, in early chronic phase a Ph-negativ e autograft could be obtained in three out of eight patients upon mobi lization with '5 + 2' chemotherapy. Thirty-one patients underwent PBSC transplantation and all of them successfully engrafted, Post-transpla nt cytogenetic analysis was available on 21 cases, of whom seven achie ved a complete or major cytogenetic response, with two minor cytogenet ic remissions. One patient (1/57) in blast crisis died during mobiliza tion therapy (1.8%). Transplantation related mortality was 0%. This st udy demonstrates that mobilization of Ph-negative PBSC after myelosupp ressive chemotherapy is feasible in CML patients and is associated wit h acceptable toxicity. Autologous transplantation of irt vivo purged P BSC is a safe procedure with rapid and complete hematopietic recovery.